<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta http-equiv="X-UA-Compatible" content="IE=edge">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
</head>
<body>
  <script>
    // var i = 1
    // do {
    //   console.log('你真好')
    //   i++
    // } while(i < 10)

    // 先执行一次，再去判断条件
    do {
      var message = prompt('吃了吗')
    } while(message !== '吃了')
  </script>
</body>
</html>